ASTM Specification E1993-98 is the standard specification for bituminous water vapor retarders used in contact with soil or granular fill under concrete slabs. That specification deals with a bituminous membrane water vapor retarder consisting of asphaltic materials reinforced with multiple plies of a suitable fabric. The property requirements of ASTM E1993-98 are with respect to water vapor permeance under certain conditions, tensile strength, and puncture resistance. A considerable amount of work has been undertaken in order to develop a membrane which will meet the requirements of ASTM E1993-98. This work has resulted in the development of the present disclosure which meets or exceeds that specification.